Electronic devices use radio-frequency (RF) signals to communicate information. These radio-frequency signals enable users to talk with friends, download information, share pictures, remotely control household devices, receive global positioning information, employ radar for detection and tracking, or listen to radio stations. As these radio-frequency signals travel over larger distances, it becomes increasingly challenging to distinguish the radio-frequency signals from background noise. To address this issue, electronic devices use power amplifiers (PAs) and low-noise amplifiers (LNAs) to amplify radio-frequency signals without introducing significant additional noise.
For time-division duplex operations, transmission and reception are performed at different times. Accordingly, a transmitter can generate an uplink signal for transmission at a first time and a receiver can process a downlink signal at a second time. In some situations, an antenna is used to transmit the uplink signal and receive the downlink signal. However, it may be challenging for some interface approaches to provide sufficient isolation between the transmitter and the receiver. As an example, an interface approach may use a switch to selectively connect the transmitter or the receiver to the antenna. For some semiconductor manufacturing processes, however, it may be difficult to design the switch to provide sufficient isolation. It may also be challenging to design the switch to provide sufficient isolation at higher radio frequencies (e.g., millimeter-wave frequencies). Without sufficient transceiver isolation, a signal-to-noise ratio performance may degrade and increase power consumption of the transmitter or limit long-distance detection capabilities of the receiver.